Grand Canyon blaze grows into a megafire and creates its own weather. It's not done yet

CNN

3 days ago

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The wildfire raging along the Grand Canyon's North Rim became a 'megafire' this week, doubling in size in just a few days and intensifying enough to create its own weather.
Hostile weather conditions including intense, dry heat and gusty winds drove the Dragon Bravo Fire's explosive growth and erased much of the containment progress made by fire crews.
The northern Arizona fire has burned through nearly 112,000 acres since igniting on July 4 and was 9% contained as of Friday morning, according to the National Interagency Fire Center. It's the largest fire currently burning in the lower 48 states and its footprint is about three times the size of Washington, DC.
The Dragon Bravo fire reached megafire status after crossing the 100,000-acre threshold. The blaze has more than doubled in size since Sunday, when it was around 50,000 acres, according to data from Inciweb.
Megafires like the Dragon Bravo Fire are rare — only about 3% of wildfires reach this scale — but they account for the majority of total acreage burned in the United States each year.
A lightning strike ignited the wildfire on Independence Day and crews initially chose to manage it as a controlled burn instead of smothering it immediately. The fire quickly grew out of control about a week after igniting and fire crews have been fighting to contain it ever since.
The blaze tore through the North Rim's historic Grand Canyon Lodge in mid-July and destroyed at least 70 other structures, including cabins and a visitor's center.
The fire was 26% contained — its maximum level so far — this past weekend, but worsening weather conditions this week have triggered erratic fire behavior and lowered its containment level considerably.
In fact, the fire became so intense that it created its own weather.
Pyrocumulus or 'fire clouds' were spotted over the Dragon Bravo Fire for at least seven days in a row, fire information officer Lisa Jennings told the Associated Press on Thursday.
Pyrocumulus clouds form over intense heat sources, like raging wildfires or volcano eruptions. They develop because the air above such intense heat is quickly and chaotically forced to rise, which cools and condenses the air's moisture, forming clouds.
If a wildfire is hot and chaotic enough it could even fuel a pyrocumulonimbus – a 'fire thunderstorm cloud' – that generates lightning, wind gusts and sometimes produces tornadoes. Additional lightning strikes from these types of clouds could set off new blazes or reignite areas crews have already smothered.
Even outside of the weather the fire creates for itself, conditions will remain challenging through at least early next week, if not beyond. An extreme heat warning is in effect for the Grand Canyon through Tuesday and periods of gusty winds will not relent into early next week.
Frequent wind gusts of around 20 to 25 mph will occur Friday and through the weekend before gusts up to 30 mph pick up early next week.
CNN Meteorologist Briana Waxman contributed to this report.